Method for forming dies.



W. J. MAOFARLAND & W. G. EATON.

METHOD FOR FORMING DIES.

APPLIOATION FILED JUNE 19, 1908.

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' plate 3 plate of plastic such as plaster of Paris groove cut UNITED STATES PATENT OFFICE.

WILLIAM J'. MAUFARLAND, 0F EVERETT, AND WILLIAM Gr. EATON, OF BOSTON, MASSACHUSETTS.

METHOD FOR FORMING DIES.

Specification of Letters Patent.

Patented Mar. 12, 1912.

Application filed June 19, 1908. Serial No. 439,468.

I it of which the following is a specification.

This invention relates to an improved method for forming cast dies to be used in cutting blanks in the manufacture of shoes or other articles and has for its object the production of a die capable of performing the work for which it is designed, which may be produced quickly and at a minimum of expense. Heretofore devices of this class have been produced from forged steel at considerable expense and with much labor. By our improved method. this extra labor and expense is dispensed with.

The invention consists in suspending a or other suitable material or clay above a suitable pattern plate of a shape which it is desired should be reproduced in a cutting die and following the outline of said pattern with a revoluble cutting member, the end of which is preferably tapered and adapted to cut into the plate of plastic material a continuous groove the side walls of which preferably are converging and the bottom of which throughout its length lies in the same horizontal plane. The plate of plastic material is then removed from the supporting members and a type metal or other suitable material is poured into the by said cutting member, in this manner producing a suitable pattern con forming to the outline of the blank which it is desired to cut. This pattern is then inserted in a suitable flask containing sand which upon removal will form in the usual manner a cavity in the sand, in which may be cast in steel a die adapted to be used for cutting blanks when its edges have been sharpened with the cutting edge at every point in the same horizontal plane.

In the drawings, which represent certain apparatus which is used in carrying out this improved method of forming dies,--Figure 1 represents an elevation partly in section of a device for supporting the plate of plastic material, the pattern support, and the device for operating the revoluble cutter to cut a groove into the plastic material conforming to the shape of the supported pattern. Fig. 2 represents a partial horizontal section of the same on line 22 on Fig. 1, looking in the direction of the arrow. Fig. 3 represents a plan of the plate of plastic material when the groove or shell has been out therein. Fig. 4: represents a perspective view of the pattern cast in said plastic material. Fig. 5 represents a cross section through one of the cutting blades of said die. Fig. 6 represents a plan of one part of the flask with the pattern inserted in the sand therein. Fig. 7 represents a vertical section of the same, the cutting plane being on line 77 on Fig. 6 with the pattern removed. Fig. 8 represents a vertical section of the flask complete preparatory to pouring the molten steel therein to form the cutting die, and Fig. 9 represents an elevation of the cutting die cast within said flask.

Similar characters designate like parts throughout the several figures of the drawings.

In the drawings, 10 represents a suitable table which has secured thereto uprights 11, the upper ends of which are adapted to support a casing 12 having embedded therein a plate of plastic material 13, said casing being held in posit-ion on said uprights 11 by means of the bolts 14 and nuts 15.

Secured to the table 10 beneath the plate of plastic material 13 is a support 16 to the upper end of which is secured by means of the clamp screws 17 a pattern plate 18 which may be of any desired shape. Between the head 19 of said support 16 and a collar 20 secured to the shank of said support is interposed a slotted plate 21 through the slot 21 of which the shank of the support 16 extends. Secured to the plate 21 is a suitable handle 22, the inner end of which is forked and provided with bearings 23 for a revoluble cutting tool 24 the upper end of which is tapered and provided with suitable cutting edges as indicated in Fig. 1. This tool 24 may be revolved in any suitable manner, as, for instance, by means of the flexible driving member 25. In the bifurcated end of the handle 22 and surrounding the shank of the tool 24 is a suitable flanged wheel 26 the flanges of which are adapted to coincide with the upper an d may seize the handle 22 and move itabout the axis of the support 16, the wheel 26 following the outline of the pattern plate 18 and thereby cut into the sheet of plastic material 13, a continuous groove, the outline of which is the same as the pattern plate 18 except that it is slightly larger as indicated by dotted lines in Fig. 2.

The flanges of the wheel 26 prevent any endwise movement of the tool 24 so that when the groove or channel 29 has been cut into the sheet of plastic material the inner ends of the converging walls will all be in the same horizontal plane. The plate of plastic material is then capable of being used as a matrix from which a suitable pattern may be formed if suitable metal or other material is used in the formation of the pattern.

It is not practical to use a matrix of plastic material for the production of the cutting die itself from steel as the intense heat of the molten metal is liable to crack the material and make the pattern useless. For this reason type metal or other similar material is used in connection with the sheet of plastic material to form a pattern which may be ultimately used in the ordinary mold or flask, as will be hereinafter described. A matrix may be used, however, composed of compressed material such as sand or clay, into which the groove may be cut and in which a casting may be formed in the usual manner.

WVhen the molten type metal or its equiva lent is poured into the groove 29 and allowed to harden a continuous pattern 30 of a die of the required outline is secured, as indi cated in Fig. 4, the cross section of every portion of the blade of which is shown in Fig. 5. The pattern 30 is then inserted in a flask 31 of any well-known construction, said flask being supplied with the usual sand 32. When the sand has been packed down sufficiently about the pattern 30, the pattern is removed as indicated in Fig. 7 and the top part 33 of the mold is placed in position and the various parts secured together by the bolts 34 and nuts 35. The molten steel is then poured through the opening 36 into the cavity 37 formed by the removal of the pattern 30 from the sand 32. Nhen the casting has been completed the die 38 is removed from the mold or flask is hardened and the sides chamfered ofl to form a cutting'edge,

said cutting edge being in the same horizontal plane throughout its length. When a groove has been ,cut into. the sheet. of plastic material, from the pattern shown in the drawings,'this pattern may be removed from its support and a larger or smaller one substituted therefor and the operation repeated, thereby forming in said sheet of material a plurality of grooves in which'a plurality of patterns may be simultaneously formed. When the patterns have been used to form the required number of castings these patterns may be melted and the material used over and over again in the formation of other patterns.

It is obvious that any suitable construction of mechanism may be used in carrying out the invention without altering the principles of the invention.

While the drawings show and the specification describes the invention particularly to the construction of cutting dies it is obviousthat it may be applied equally as well to the production of castings to be utilized for other purposes. I

By such a method of constructing dies a die is produced with very little labor which is capable, when hardened and sharpened, of use in cutting the blanks to be used in the manufacture of boots and shoes or other articles and such production is secured at very little expense.

It is believed that with the foregoing explanation the many advantages of this improved method of manufacturing dies will be fully apparent without any further description.

Having thus described our invention, We claim: I

1. The method of forming dies, which consists in supporting a plastic plate opposite a pattern plate, cutting a groove into said plastic material with a revoluble tool following the edge of said pattern plate,

casting a pattern of soft metal in said groove, inserting said soft metal pattern in the sand of a mold, removing the soft metal pattern from said sand, and casting in'the cavity formed thereby in the sand a continuous die with converging sides.

2. The method of forming dies, which consists in supporting a plate of fine-grained plaster opposite a pattern plate, cutting a groove into said plate of plaster with a tool following the edge of said pattern plate, said tool having a movement independent of its movement along the edge of said pattern plate, casting a pattern of soft metal in said groove, inserting said soft metal pattern in the sand of a mold, removing the soft metal pattern from said sand, and casting in the cavity formed thereby in the sand a continuous die with converging sides.

3. The method of molding uniform arti 'cles, which consists in first supporting a as applied sheet of plastic material opposite a pattern casting metal into the cavity formed by said 10 plate, cutting into said sheet of material type metal pattern in the second mold.

with a revoluble tool following said pattern Signed by us at 7 Water st., Boston, Mass, plate to form a mold, then pouring type this 13th day of June, 1908.

metal into said mold to form a pattern, then WILLIAM J. MACFARLAND. embedding said type metal pattern in suit- WILLIAM G. EATON.

able molding material to form a second Witnesses:

mold, then removing intact said type metal WALTER E. LOMBARD,

pattern from said second mold, and pouring NATHAN C. LOMBARD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

